Controls for pipe drifting machines



Jan. 26, 1960 w. M. M CONNELL 2,922,944

CONTROLS FOR PIPE DRIFTING MACHINES 2 Sheets-Sheet 1 Filed Nov. 25, 1957IN VEN TOR. William M. Ma Gonna/l BY W I Y- H/S ATTORNEYS Jan. 26, 1960w. M. MCCONNELL CONTROLS FOR PIPE DRIFTING MACHINES 2,922,944 Filed Nov.25, 1957 2 Sheets-Sheet 2 INVENTOR. McConnell BYW ZZ Mnozi-g o m HIS .4TTOR/VEYS William M.

United St 2,922,944 CONTROLS FOR PIPE DRIFTIN G MACHINES William M.McConnell, McKeesport, Pa., assignor to Taylor-Wilson ManufacturingCompany, McKees Rocks, Pa., a corporation of Pennsylvania AppiicationNovember 25, 1957, Serial No.

3 Claims. (Cl. 318286) This application is a continuation-in-part of mycopending application Serial No. 419,889 filed March 30, 1954.

mandrel through a length of pipe.

In the production of commercial pipe and tubing, mantlfacturerscustomarily pass a drifting mandrel through tdrifted its entire length.

My invention provides a pipe drifting machine .control w ic having adrifting mandrel and means for reciproa control comprising means fordetermining the amount of advancement of the mandrel through a pipe.Connected thereto is a signal gencrating means whichcontrols the meansfor reciprocating the drifting mandrel.

In the accompanying drawings I have described a preferred embodiment ofmy invention in which:

Figures 1 and 1A comprise a plan view of a pipe drifting machineequipped with my control;

Figure 2 is an end view along the line IIII of Figure 1;

Figure 3 is a sectional view along the line IHIII of Figure 1; and

Figure 4 is a diagram of electric circuits used in my control.

Figures 1 and 1A show a pipe drifting machine emtes Patent 2,922,944Patented Jan. 26, 1960 bodying my invention which machine has aconventional pinch roll Then electric motor 3 which drives the pinchroll stand is reversed and the drifting mandrel pipe. The driftingmandrel com- 4 and head corresponds to the specified inside diameter ofthe length of pipe. A pipe handling table 6 supports the the driftingmandrel so that the drifting mandrel may be readily reciprocated insidethe length of pipe.

cable taut and preventing fouling. is stalled during advancement of thedrifting mandrel and also when the mandrel bar is against the stop 10,Figure 3.

Rotation of the shaft 12 resulting from unwinding the cable 14 from thedrum drives a gear reducer 17 which in turn rotates spindle 18 connectedto the rotor of a synchro generator 19. The drum 11, shaft 12 and 17accurately and continually Thus the amount of rotation of the motor ofthe synchro generator is proportional to the amount of advancement ofthe drifting mandrel.

As shown in Figure 4 an AC. excitation bus line 20 supplies power to thesynchro generator. Connected to the synchro generator is a synchrotransformer 21 to which is connected a conventional electronic amplifier22. A magnetic amplifier is interchangeable with the electronicamplifier. The excitation bus line also supplies power to the electronicamplifier 22. The electronic amplifier 22 actuates a relay 23 whichcontrols the operation through cam limit switch 26 conrotation of therotor is lessthan 180 push button 29 or the relay leads 24 the'closedpush button 29 or transformer 21 and the amplifier 22 nected to the busline 20.

synchro generator nected thereto and. itself connected to the armatureof the motor 3 to reverse the pinch roll stand when the drifting mandrelhas reached the endof the length of pipe.

It is well known generator and of the synchro transformer are in thesame angular position or in positional agreement the voltage across therotor of the synchro transformer is zero and when they are not in thesame angular position there is a voltage across the rotor of thissynchro transformer. rotating the rotor f. thesynchro transformer toplace it in a different angular position from. that of the rotor of the]synchro generator I causea voltageon the leads Z4 and connecting thesynchro transformer to the electronic amplifier. It is this voltage orthe absence thereof across the leads 24 and 25 which I employ to controlthe operation of the pinch roll stand. 7

The operation of 'my pipe drifting mac ine control is substantially asfollows. First, I set chine to travel a distance corresponding to thepipe in question by turning the transformer to. a position correspondingto the length of the pipe and there locking it in position. The amountof out of positional coincidence with the rotor of transmitter 19. Threefactors determine the amount of rotation of the rotor of the synchrotransformer 21. These are the length "of the pipe to be drifted, thediameter of the drum 11 and the ratio of the number of revolutions ofthe drum 11 to' the number of revolutions of the rotor of the synchrogenerator 19. rotation of the rotor of the synchro transformer places itin a different angular position from that of the rotor of the synchrogenerator and thereby causes a'volta'ge. across the leads 24and 2.5.

the length of INext I close push button 29 or cause relay 28 to close ywhich pipe, upon (not shown) controlling the relay 28 connects thevoltage across delivering a length of pipe to the pipe drifting machinedelivery to the machine, trips a switch shown) therein. When theamplifier 22 is actuated, either the closed relay28 opens. Closing thenormally open relay in the amplifier 22 energizes relay 23 which hasthree contacts 32. Contacts 30 and 32 are normally open and contact 31is normally closed so that when relay 23 isenergized, contacts 30 and 32close and contact 31 opens, Contact 30 controls a circuit connected tothe electric'motor 3 so that when, it is closed, the motor advances thedrifting mandrel 2 through a length of pipe. Contact 31 controls anelectric circuit connected to the electric motor 3 so that when it isclosed, the motorfi reverses and'returns the drifting mandrel breaks theelectrical connection between when 30 and 31 are conthesynchrodeenergized. As shown, contacts 'During advancement of thedrifting mandrel the amount of this advancement is accurately andcontinually measured by the drum 11 and the second gear reducer 17 whichrotates the rotor of the synchro generator an amount proportional to theamount of advancement of the drifting mandrel. The rotation of the rotorof the transmits a signal to the stator of the synchro transformer. Thisrotation of the rotor of the synchro generator continues until the rotorof the synchro generator and the rotor of the synchro transformer areonce again in thesame angular position at which time the voltage acrossleads 24- and 25 connecting the synchro transformer to the electronicamplifier is zero. When the rotor of the synchro transformerand therotor of the synchro generator are onceagain in the same angularposition, the drifting mandrel has advanced an amount equivalent to thelength of the pipe, The amount of advancement of the drifting mandrel 2as measured by the rotor of the synchro generator that when the rotorsof the synchro.

rotor of ,the 4 synchro This 28. Closing. either the so, 31, and v therelay- 23 1S 7 19 corresponds to the amount of rotation of the , openand contact 31 to close. Opening contact 30 halts the pipe driftingmaand 25 to the amplifier 22', whereupon the am 'plifier is energizedand closes a normally open relay (not drifting operation.

advancement of the mandrel and opening contact 32 electricallydisconnects the'synchro-transformer from'the amplifier 22. Closingcontact 31 causes the motor 3 to reverse and withdraw the drift mandrel;The drifting mandrel continues to withdraw until it reaches its startingposition, whereupon a normally closed contact (not shown) in cam limitswitch 26 opensand interrupts the reverse control circuit of the" motor3. The drifting mandrel then remains at its starting position untileither push button '29 or relay 28 closes. p

The cam limit switch26 which is connected to the second gear reducer 17through spindle 27 also functions as a safety deviceto drel in the eventthe synchro transformer and synchro generator fail to operate. This camlimit switch is con nected to conventional electric circuits (not shown)which control the operation of the pinch roll stand if the synchrotransformer and synchro generator fail. The cam limit switch reversesthe pinch roll stand after a predetermined amount of advancement of thedrifting mandrel over and beyond the length of'the pipe in question.' i

I Since my invention accurately controls the amount. of advancement ofthe drifting mandrel it is highly useful to manufacturers of largetonnages of pipe and tubing, in that delivery of pipe is notunnecessarily delayed by the My control permits a pipe manufacturer toefficiently drift large tonnages of pipe irrespective of whether theyare the same size or'varied sizes.

T he operator has only to ,set'thecontrol for the length of pipe to bedrifted and thenwait for the next pipe while the machine automaticallyperforms the entire operation.

' change in-lengthQ He does not have to move from his station at thecontrol to make any adjustment on the drifting to its starting position.Contact 32.

apparatus to take into account a different length of pipe.Pipemanufacturers need n'o longer rely upon the, ability of a'pipedrifting machine'operator to reverse the pinch roll stand when hebelieves the drifting mandrel has reached the: end of the pipe;Therefore, it is apparent that rny control is especially usefulfor theautomatic production of large tonnages of'pipe; f

While a certain present preferred embodiment of my invention has beenshown and described, it will be understood that it may be otherwiseembodied within the scope of the appended claims. a

I claim 7 1. In a pipedrifting machine, the combination comprising adrifting mandrel, means for reciprocating said drifting mandrel on saidmachine, a rotatable drum, a cable'woundu'pon said drum and having oneend connected to said drifting mandrel so that advancement of saiddrifting mandrel rotates said drum, means operated by rotation of saiddrum for determining the amount of advancement of said drifting mandrel,signal generating means actuated by said means operated by rotation andmeans responsive to a signal from said generating means for controllingsaid means for reciprocating said mandrel. V v V V 2. 'In a pipedrifting machine, prising a drifting mandrel, means drifting mandrel onsaid machine,

the combination comfor reciprocating said a rotatable drum, a

cable wound upon said drum and having one end con-- the rotor of thesynchro trans former 21 when the rotor of the synchro transformer was todeenergize. De-,

prevent overtravel of the drifting mandrel rotates said drum, meansconnected to said drum for maintaining tension upon said cable duringadvancement of said mandrel and for winding return of said mandrel,means operated by said drum for determining the amount of advancement ofsaid mandrel, a synchro-generator actuated by said means operated bysaid drum, a synchro-transformer electrically connected to saidsynchro-generator, and means respon sive to said synchro-transformer forcontrolling said means for reciprocating said mandrel.

1,325,925 Bristol Dec. 23, 1919

